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Hi, I have noticed some performance issues on my RHEL5 server but the memory and CPU utilization on the box is fine. I have a 1G full duplexed eth0 card ...
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  1. #1
    Just Joined!
    Join Date
    May 2012
    Posts
    8

    Eth0 Limitations


    Hi,

    I have noticed some performance issues on my RHEL5 server but the memory and CPU utilization on the box is fine.

    I have a 1G full duplexed eth0 card and I am suspicious that this may be causing the problem. My eth0 settings are as follows:

    Settings for eth0:
    Supported ports: [ TP ]
    Supported link modes: 1000baseT/Full
    10000baseT/Full
    Supports auto-negotiation: Yes
    Advertised link modes: 1000baseT/Full
    10000baseT/Full
    Advertised auto-negotiation: No
    Speed: 1000Mb/s
    Duplex: Full
    Port: Twisted Pair
    PHYAD: 0
    Transceiver: internal
    Auto-negotiation: on
    Supports Wake-on: g
    Wake-on: d
    Link detected: yes

    ........and my current Rx & Tx figures are as follows.

    ifconfig eth0
    eth0 Link encap:Ethernet HWaddr 9C:8E:99:31:34:A0
    UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1
    RX packets:75042475 errors:0 dropped:0 overruns:0 frame:0
    TX packets:105451412 errors:0 dropped:0 overruns:0 carrier:0
    collisions:0 txqueuelen:1000
    RX bytes:3906089934 (3.6 GiB) TX bytes:269789061 (257.2 MiB)

    Can anybody tell me what the limitations of this card is? As a percentage is it currently under stress or is it normal and well within its limitations?

    If all looks well I'll examine the app in much more detail but really need to rule this out firstly.

    Tkx,
    Harry.

  2. #2
    Linux Newbie
    Join Date
    Apr 2012
    Posts
    112
    You can use sar to generate reports of system activity information, e.g.
    Code:
    sar -n DEV
    will give network statistics and
    Code:
    sar -n EDEV
    will include errors.

    You can start and stop sar at particular times with -s & -e respectively

    You don't specify what type of app you are having issues with or indeed what type of performance issues.

    Generally speaking the network is the limiting factor, but in my limited development experience (only web apps) minimizing the number of network calls is the way forward.

  3. #3
    Just Joined!
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    May 2011
    Location
    Malaysia
    Posts
    15
    Can you provide more information what kind of performance issues you're experiencing?
    Are you seeing the issues from an application?

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